1. Field of the Invention
The present invention is a juice extraction system, and more particularly, a system for dejuicing grapes and the like.
2. Description of the Prior Art
In the wine industry, grapes may be hand picked or may be harvested by mechanical pickers or strippers. After picking, it is imperative that the grapes get to the destemmer as soon as possible to prevent deterioration of the quality of the grapes. However, many large wineries experience delays in unloading the harvested grapes from the trucks and several hours wait is not unusual. Such delays may be due to the relatively slow processing time and lack of holding facilities. When the grapes are introduced into the destemmer, the process of removing the grapes from the stems causes crushing and breaking of the skins of a portion of the crop. This produces what is known as "free run" juice, as well as breaking loose solids which mix with the juice. Because of the free run juice generated in the destemmer, it is necessary to predrain the must before final pressing. A number of systems are in current use, such as the Potter system in which the must from the destemmer along with the free run juices are introduced into large tanks in which the juice is allowed to settle. After a few hours, the settled juice is pulled from the tanks and taken to separators, such as centrifuges, which remove solids from the juice. The predrained must, which may still contain free run juice, is then dumped into conveyor troughs to carry the must for further processing.
Other predraining systems may include drag screen devices in which the must is carried on open belt type conveyors with collecting pans below the conveyor surfaces allowing the free run juice to drain by gravity as the must is carried along. Other systems deposit the must on flat screens and the must is then pushed along the screen by conveyor paddles allowing the juice to filter through the screens into collecting pans. These systems are relatively inefficient and slow and therefore contribute to processing delays. After the must has been removed from the settling tanks or from the drag screens, the must may be introduced into the final presses which remove the majority of the remaining juices.
The rate at which grapes may move through a winery is, of course, a function of the capacity and the processing times required by each step or phase of the operation. While such times may vary greatly, a typical operation for handling 50 tons of grapes may be as follows:
(1) destemming--one hour; PA1 (2) settling in Potter tanks--two hours; PA1 (3) dumping the must into conveyor trough or pump--1/2 hour; PA1 (4) pressing--one hour.
The original 50 tons of grapes will lose about 42,500 pounds of juice, leaving about 281/2 tons of must after predraining and pressing. At 4 to 41/2 hours for processing gives a rate of about 71/2 tons per hour. It is an object of the present invention to provide a system for extracting juice from grapes and the like which will require less handling and transporting, and have higher efficiency and throughput rates than the above described systems. Such a system can therefore handle incoming grapes without significant delays between picking and processing, resulting in higher quality juices and greatly reduced operating costs.